The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 16, 2002
Filed:
Nov. 06, 1997
Eiichi Hoshino, Kawasaki, JP;
Masanori Onodera, Kawasaki, JP;
Naoyuki Ishiwata, Kawasaki, JP;
Kazumasa Doi, Kawasaki, JP;
Mitsufumi Naoe, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A transparent optical device is provided with a transparent medium having a front side, at least a portion of the front side being adapted for receiving light. A porous layer is formed on substantially all areas of the front side which are adapted for receiving light. The transparent optical device may have a recessed surface area which is recessed below a remainder area of the front side to define a phase shift photomask. The transparent medium may be made of synthesized silica. The porous layer may be formed by reactive ion etching using gaseous plasma of halogenized hydrocarbon. The front side of the transparent medium may have a portion not adapted for receiving light which may have a metal pattern formed thereon. In producing the transparent optical mask, the porous layer may be formed before or after the metal pattern. The transparent optical device may be formed in an etching chamber in which etching depth is monitored by measuring the transmissivity of a preselected portion of the transparent medium.